Biological fluids concentration assembly

ABSTRACT

A biological fluids concentration device, including a tube-in-tube assembly, is disclosed. The tube-in-tube assembly receives biologic fluids and may then be placed in the bucket of a centrifuge and spun to separate out the components of the biological fluid by their various densities. For example, whole blood may be centrifuged in the tube-in-tube assembly for separating into plasma, red blood cell component, and a buffy coat. A piston slideably and sealingly engages an inner tube of the tube-in-tube assembly, the inner tube fitting within an outer tube. A lid is designed to engage the top of the outer tube, which lid has an opening therein for receipt of a plunger. The plunger is adapted to move up and down with respect to the lid and the tubes, so as to sealingly, in a down position, and unsealingly, in an open position, engage the top of the inner tube of the tube-in-tube assembly.

RELATED APPLICATIONS

This application is a divisional application of and claims priority andbenefit to U.S. patent application Ser. No. 14/226,248, filed on Mar.26, 2014, which is a utility patent application claiming priority fromand the benefit of U.S. Provisional Patent Application No. 61/805,346,filed Mar. 26, 2013; and U.S. Provisional Patent Application No.61/880,485, filed Sep. 20, 2013. All of these applications areincorporated herein by reference.

FIELD OF THE INVENTION

Concentration assemblies, namely, concentration assemblies adapted toconcentrate biological fluids under centrifuge.

BACKGROUND

Biological fluids, such as blood, bone marrow aspirate, and the like,are often subject to centrifuge so as to separate them by density intotheir separate components. For example, blood, when centrifuged, willseparate into red blood cell components (denser) and a plasma component(less dense) with a small percentage of buffy coat between. Bone marrowaspirate, when centrifuged, will typically separate into a red bloodcell (platelet) component, a plasma component, and a buffy coatcomponent comprising stem cells or undifferentiated cells.

SUMMARY OF THE INVENTION

Applicant provides a fluid concentration assembly that has a “cup withina cup,” wherein the inner cup is adapted to receive a biological fluidand has a gap between it and the outer cup. The concentration assemblyis adapted to be received into a centrifuge machine and subject tocentrifugation. Following centrifugation, a piston in the inner cuppushes up from below on the separated contents to force spillover of theless dense liquid into the gap, until the desired component is at thetop of the inner cup. At this point, the open top of the inner cup maybe sealed with a moveable sealing member and the piston driven furtherupward into a collection vessel engaging the sealing member.

In certain embodiments, the biological fluids concentration assemblyincludes a tube in tube assembly having a cylindrical outer tube and acylindrical inner, smaller diameter, tube both having open tops and openbottoms. The open top of the inner tube is located below the top of thelarger (outer) tube. A base engages the outer and inner tubes at thebottom ends thereof, the base allowing fluid communication between theexterior of the tube assembly and the interior of the inner tube. Apiston is provided for slidably and fluid sealingly engaging the innerwalls of the inner tube above the base and below the top. A lid isprovided for sealing tightly to the open top of the outer tube, the lidhaving a central opening or bore. In certain implementations, the lidalso has anti-rotation tabs attached to the surface thereof. A plungerassembly engages the tube in tube assembly and includes a plunger and anexternal cap with inner rim walls defining a central bore. The innerwalls may also have projecting bosses. The cap includes walls configuredfor rotatable engagement with the lid. The plunger has a base and a neckengaging the base, the plunger having a fluid channel therethrough. Theneck has drive tracks that engage the bosses of the external cap.Rotation of the external cap moves the plunger from an open positionwherein the lower surface of the base is off the open top of the innertube to a closed or down position, wherein the lower surface of the baseengages the open top of the inner tube so as to fluidly seal it.

The plunger includes a channel for fluid communication through theplunger from the top surface of the plunger to the bottom surface. Thechannel bottom opening is positioned over the inner tube. Thus, a fluidcontaining device (e.g., a syringe) containing a fluid may be coupled tothe top of the neck of the plunger (usually in the up or open position),as by threadable engagement, and a fluid, such as a biological fluidneeding centrifuge separation, may be urged through the plunger into theinner tube. The plunger can then be moved to a closed position where thebase of the plunger seals the top of the inner tube (thus avoidingspillage), and the entire assembly may be inserted into a centrifuge andspun. Following centrifuging, the piston in the inner tube may be drivenupward. If the piston is driven upward and the plunger is in the up oropen position, the less dense fluid (typically plasma) will be the firstto spill over into a gap between the inner tube and the outer tube. Whenthe less dense fluid is all or mostly all spilled over into the gap, thetarget of collection (usually the buffy coat) will be at the top of theinner tube. The user may then move the plunger to a closed position, asby rotating the external cap. In the closed position, the plunger isfluidly sealed against the upper perimeter of the inner tube. Furtherurging upward of the piston will force the fluid in the inner tube (thecentrifuged separated fluid) into an empty fluid collection device(e.g., a syringe) attached to the neck of the plunger.

In particular implementations, the tube in tube elements are made of aclear material, such as clear plastic. Thus, the user may observe as thepiston is urged upward and the centrifuged fluid is urged into aspillover situation or into a syringe engaging the top of the neck andselectively choose when to cease urging the piston upward, for example,when a buffy coat is substantially received within the fluid receivingsyringe. The selected liquid may be collected in the syringe after theplunger is moved to the down position, by either suction from thesyringe or pushing up on the piston.

In some embodiments, a fluid, such as a saline solution, may be driveninto or withdrawn from the portion of the inner tube that is beneath thepiston by use of a syringe that may be threaded into a fluid deviceinterface engaging the base of the tube in the tube assembly. That is tosay, the base of the tube in tube assembly provides for fluidcommunication into the inner tube and also seals the bottom of the innertube.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an example biological fluidsconcentration assembly.

FIG. 1A is a perspective exploded view of the biological fluidsconcentration assembly.

FIG. 2 is a perspective view illustrating the use of a tool with theassembly.

FIG. 3 illustrates in perspective view the manner in which a syringewith a biological fluid therein may engage Applicant's biologicalassembly to substantially fill an inner container.

FIG. 3A shows a post-centrifuge pre-withdrawal condition of Applicantscollection cup.

FIG. 3B illustrates the spillover step, wherein the less dense plasmahas been urged up and out of the inner container into the larger cup.

FIG. 3C is a cross-sectional perspective view of a holding device foruse with Applicant's cup assembly.

FIG. 4 is an exploded perspective view of another example biologicalfluid concentration assembly.

FIGS. 4A and 4B are cross-sectional views of the second biological fluidconcentration assembly in an open and a closed position, respectively.

FIGS. 5 and 6 are perspective exploded detail views of the plungerassembly and lid of the second example biological fluid concentrationassembly.

FIGS. 7, 7A, and 8 are closeup views in cross-section of the plungerassembly and lid of the second example concentration assembly, with FIG.7 showing the manner in which the bosses of the inner walls of theexternal cap engage the drive tracks of the neck of the plunger, FIG. 7Ashowing the plunger in the closed position, and FIG. 8 showing themanner in which wedges on the outer surface of the inner walls of thecap engage an inwardly extending lip of the lid to capture the cap onthe lid in such a fashion that the cap can rotate.

FIG. 9 is a perspective view showing the upper surface of the cap on thelid, showing a locking snap ridge protruding from the end of the ridgeto prevent unintentional twisting.

FIG. 10 is a perspective view of the second example fluid concentrationassembly showing the manner in which a piston drive syringe is used forengagement with a base, as well as a manner in which a biological fluidscylinder is engaged with the fluid device interface and the neck of theplunger.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A first embodiment of a fluid concentration assembly 10 (FIGS. 1A-3C)includes a container-in-container assembly 12 having an outer container14 with a cup or tube interior and an inner container 24 with a tubeinterior with an open bottom 30 and open top 28, the top within theinterior of outer container 14. Piston 32 is adapted to be slideably andsealingly received within open bottom 30 of inner container 24 asillustrated and typically includes a perimeter groove 34 with anelastomeric O-ring 36 (or other suitable sealing member) on acircumference thereof for fluid sealing against the inner walls of innercontainer 24. A lid 38 is seen to engage an open top 18 of outercontainer 14. Outer container 14 is typically cylindrical and isdimensioned to receive inner container 24 there within, such that theinner container has a smaller diameter than the outer container 14, andhas an open top below the open top of outer container 14. Outercontainer 14 has side walls 16 and an upper perimeter 19 defining opentop 18. A bottom wall 20 partly closes the bottom of outer container 14,but has an inner perimeter 30 a that defines an open bottom area 30 (seeFIG. 1A).

In the illustrated implementation, the outer wall of inner container 24touches, and may be integral with, the inner wall of outer container 14.Thus, inner container 24 and outer container 14 share a portion of awall in common. In other implementations, the outer wall of innercontainer 24 may not touch the inner wall of outer container 14.

Turning to lid 38, lid 38 is seen to have a cylindrical cover 40dimensioned to receivably and removably engage open top 18 in a snugtight manner. Cover 40 is seen to have a rim 41 that is about the samediameter as open top 18. A port 42 is provided through cover 40 toprovide gaseous communication between the interior of container 14 andthe exterior thereof. Port 42 may be closed by a plug 45. Cover 40 alsoincludes a bore 39 defined by threaded walls 44, which are adapted toreceive a threaded section 54 of a moveable plunger 46. The engagementof threaded section 54 and threaded walls 44 of cover 40 allows thelongitudinal movement of plunger 46 inward or outward as shown by thearrows adjacent thereto in FIG. 1.

In FIGS. 1 and 1A, plunger 46 includes a neck or body 47 that has anexterior open end 48, which includes a threaded section 52 for receiptof a cap 53 threadably thereon, which will substantially seal exterioropening 48. Body 47 is seen to have an exterior portion, an interiorportion, and an interior open end 50. Body 47 has an inner channel,which provides fluid communication between exterior open end 48 andinterior open end 50, which interior open end opens above the interiorof the inner container 24 and which exterior open end 48 is exterior ofthe cover. Interior open end 50 includes a base or cone-shape member 58that extends outward from interior open end 50 and is positioneddirectly over open top 28 of inner container 24. Member 58 has an openapex 60, which is sealed to a perimeter interior open end 50. Member 58is seen to have an outer perimeter 62 adapted, for example, beingcup-shaped or arcuate shaped, so as to receive sealing member 64 (hereindepicted as a resilient O-ring, although it could be another elastomericsealing member). The perimeter 62 and the sealing member are dimensionedand the moveable plunger 46 is dimensioned relative to cover 40, suchthat the longitudinal movement of plunger 46 may seat or unseat sealingmember 64 against open top 28 of inner container 24. Plunger 46 is alsoseen to have tool engaging walls 49, such that a tool 57 (see FIG. 2)may engage the tool engaging walls of the plunger, so as to rotateplunger 46 with respect to (fixed) cover 40 so as to advance sealingmember 64 from an open position (open top 28 unobstructed) to a closedposition (sealing member 64 against open top 28, such that it is nowclosed). Plunger 46 may also be retracted so as to open open top 28.Cover 40 is seen to have an alignment boss 59, and open top 18 has a rimcutout 63, so as to properly align plunger 46 such that the perimeter 62is directly above open top 28 and, further, to prevent the rotation ofcover 40 when tool 57 is used to rotate moveable plunger 46.

In operation, briefly, the physician will collect a biological fluid BFfrom a patient and then physically engage a syringe or other biologicalfluid collection device to the top of the concentration assembly asindicated in FIG. 3. The plunger 46 may be in an open or closed positionat this point. The physician will then push the plunger or otherwisecause the biological fluid BF to flow through the moveable plunger intothe inner container. Piston 32 will be at or near the bottom of theinner container. Typically, the inner container 24 will be substantiallyfilled with biological fluid BF (see FIG. 3).

The syringe is then removed, and the assembly is taken to a centrifugeand spun. In some implementations, plunger 46 may be moved to a closedposition before centrifuging. During spinning, the fluids comprising thebiological fluids will separate out according to their densities (seeFIG. 3A). FIG. 3A shows a biological fluid (here, bone marrow aspirate)with three components: red blood cell RBC (most dense), plasma P (leastdense), and buffy coat BC (typically comprising undifferentiated or stemcells), the buffy coat being intermediate between the plasma and the redblood cells. FIGS. 3A and 1 illustrate that there may be a scale 61 withnumerals adjacent thereto along a common wall 21, for example, whichcommon wall 21 is a side wall that is common to both the inner container24 and outer container 14.

Turning to FIG. 3A, the user may note the location of the upper buffycoat/lower plasma border A as it lies adjacent indicia of the scale 61.The port 47 may then be opened and the plunger 46 raise, if it is notalready up. Following raising of plunger 46 to the open position (seeFIG. 3B), piston 32 may be urged upward by user manipulation (e.g.,insertion of a digit), forcing spillover of the plasma at the open top28 of inner container 24 into the gap. Movement is continued until theupper surface of the piston has traveled the “B” distance as measured upfrom “C” (start position of the upper surface of the piston). The P/BCboundary should then be adjacent open top 28. At this point, most, ifnot all, of plasma P has spilled over open top 28 and lies in the gapbetween the inner and outer containers. When such a level is reached,plunger 46 may be lowered and a collection device for collection of thenon-plasma portion (typically buffy coat) or whatever selected portionis left in the inner container may be achieved.

In one aspect of Applicant's device, when a collection device isthreaded to exterior open end 48 for receipt of selected fluid therein,urging upward of the piston will force, or at least assist, the selectedfluid up into the collection device. This is not the typical manner ofcollection, which is usually suction of the desired fluid from above.

FIG. 3C illustrates that a holding device 70 may be used with assembly12 in two ways. First, holding device 70 may have walls 72/74, typicallycylindrical, adapted to provide a receiving space 80 in which the outercontainer 14 may rest. Secondly, holding device 70 may have walls 74/76configured to define an assembly/piston engaging space 79, which isconfigured with an upstanding piston engaging member 78, such that uponinsertion of container in container assembly 12 into space 79,upstanding member 78 will engage the bottom of the piston when it is inthe position as seen in FIG. 3A (post-centrifuge, but pre-pushout orspillover). It is seen with respect to FIG. 3C that pressing theassembly 12 downward using guide walls defining the side walls of space79 will allow the user to observe the spillover, as well as the pistonposition so that the piston position may be stopped (the user stopsinserting or pushing downward on cup 14) when the appropriate amount ofspillover has been achieved and the piston is positioned properly (e.g.,when the buffy coat or other selected fluid has a top surface justadjacent the rim defining open top 28). The user can then move assembly12 into space 80, close plunger 46 to a closed position, and draw outthe selected fluid.

Fluid concentration assembly 10 is seen in its basic form to includecontainer-in-container assembly 12. It may also includecontainer-in-container assembly 12 in addition to either holding device70 or syringe (FIG. 3) or collection device (not shown) or anycombination of the same.

FIGS. 4-10 illustrate a second example of a fluid concentration assembly110. Functionally, the fluid concentration assembly is adapted toreceive fluids, such as bone marrow concentrate or whole blood. It isfurther adapted to be insertable into a centrifuge machine so that, uponcentrifuging, the fluid contents of the fluid concentration assemblyseparate, according to their densities. For example, blood willtypically separate into a plasma, buffy coat, and a red blood cellportion, the red blood cell portion being more dense and therefore belowthe plasma which will reside on top of the red blood cell component inthe fluid concentration assembly upon the completion of centrifuging. Ifbone marrow concentrate is in the fluid concentration assembly, it willtypically centrifuge out into the plasma and red blood cell component,as well as a buffy coat between the two, which may containundifferentiated cells or stem cells.

The health care professional will typically want to selectively removeone of the separated portions, for example, a red blood cell or buffycoat portion of a whole blood concentrate or a buffy coat portion of abone marrow concentrate, or other biological fluid. It is a function ofthe biological fluid concentration assemblies in general to providestructure that may selectively remove one or more portions of thecentrifuged separated fluids for later use.

Turning now to fluid concentration assembly 110, it is seen to providesome of the functions of the previous biological fluid concentrationassemblies, albeit with structural differences and certain advantagesgained thereby. The general structure of fluid concentration assembly110 may be seen to be a container-in-container assembly 112, theassembly including an inner container 124 (shown here as a tube)configured for receipt and concentric placement within an outercontainer 114 (also shown here to be a tube), the two containers held inplace by a base 122. Outer container 114 has a top outer perimeter 119defining an open top 118. Inner container 124 is seen to have a bottomperimeter 126 defining an open bottom and a top perimeter 128 definingan open top. Outer container 114 has a bottom perimeter 120 defining anopen bottom. The outer container 114 has walls 116. Inner container 124has walls 125. The two containers have an annulus 123 therebetween, andbase 122 is configured to be insertable into the bottom of the assembly,such that it seals the open bottoms of the two containers 114/124 infixed fluid sealing relation as, for example, by gluing or heat.

Apparent from FIG. 4 is that the bottom perimeters of the outer andinner containers are positioned laterally adjacent to one another, butthe top perimeter 128 defining the open top of the inner tube 124 islocated spaced apart and below the upper or top perimeter 119 of outertube 114.

It is seen how base 122 seals annulus 123 (at the bottom) therebycreating a fluid chamber in the annulus, and it is seen how the basebottom wall 195 (see FIG. 4) also fluidly seals the open bottom of theinner container. Moreover, with reference to FIG. 4, it is seen that thebase provides fluid communication in a channel through fluid deviceinterface 1105 (e.g., a needle free valve, such as those available fromHalkey Roberts Corp. of Saint Petersburg, Fla. (USA)), so that a drivefluid 127 (see FIG. 4A or 4B) may be driven through the fluid deviceinterface into the inner tube or withdrawn from the inner tube throughfluid device interface 1105. Fluid device interface 1105 may have a capthat will engage a threaded portion 1104, and may be used during thecentrifuge stage of blood processing.

In FIGS. 4, 4A, and 4B, a piston 132 is configured to slideably andfluid sealingly engage inner wall 125 of inner container 124. Piston 132may be cylindrical, as containers 114 and 124 are seen to be cylindricaland clear (see through), and piston 132 may have a walled surface with amultiplicity of grooves 132 a therein, which grooves may be adapted toreceive O-rings 132 b or other sealing elements therein. It is seen thatpiston 132 seals a fluid volume above the O-rings defined by the innerwalls of the inner container and a volume below the O-rings. A lid 136is configured typically to be glued or otherwise made fluidly sealinglyand integral with outer perimeter 119, so to be rigidly coupled thereto.

A plunger assembly 131 includes a cylindrical external cover 134 and aplunger 138. Plunger assembly 131 is adapted to engage the lid 136, andthe external cover 134 is adapted to engage the plunger 138, such thatrotation of external cover 134 moves the plunger along an axisperpendicular to the plane of rotation of the external cover, causingthe plunger to move between an up or open position as seen in FIG. 4Aand a down or closed position as seen in FIG. 4B. Moreover, withreference to FIGS. 4A and 4B, it will be seen that the open positionallows fluid residing above piston 132 to spill over into an annulus 123when piston 132 is forced upward as, for example, by action of a drivesyringe 1112 (see FIG. 10) forcing the drive fluid below the pistonupward against the underside of the piston.

Moreover, plunger assembly 131, more specifically, plunger 138, has afluid device interface 144 (e.g., a needle free valve, such as thoseavailable from Halkey Roberts Corp. of Saint Petersburg, Fla. (USA)),engaged in a body or neck 142 thereof. Neck 142 is a cylindricalprojection with a bore containing the fluid device interface, the fluiddevice interface containing a fluid channel 189 therethrough. Plunger138 contains a cylindrical plunger base 140 configured to be slideablyreceived within the outer container 114, the base having perimeterelastomeric sealing elements as set forth more specifically below. Neck142 and plunger base 140, and possibly fluid device interface 144, areintegral and define the plunger, which moves up and down as seen inFIGS. 4A and 4B, with rotation of the external cap 134 as morespecifically set forth below. Plunger base 140 may have internal vents141.

It is seen in FIGS. 4A, 4B, and 7, that the fluid device interface 144with a channel 189 therethrough is positioned above the open top of theinner container 124. If a syringe 1110 (see FIG. 10) or other fluidbearing device is engaged to the fluid device interface 144, fluid maybe forced through the fluid device interface and into the volume orspace above the piston 132 in the inner container 124. One can also seethat, if such a biological fluid were to be placed in the space abovethe piston and the plunger 138 were moved to the closed (or down)position (see FIG. 4B), centrifuging would generate separation of thebiological fluid into its components. Subsequent opening of the plungerto the open (raised) position followed by pressurizing the drive fluidbeneath the piston will cause an overflow, or a spillover, of the plasmaor other less dense fluid residing on the top of the separatedbiological fluids as the piston is forced upward. The spillover willaccumulate in annulus 123 between the inner and outer containers, andthe operator may carefully observe the boundaries between the separatedfluids. By careful observation and control of the pressure on a drivefluid syringe 1112 (see FIG. 10), the operator may position an upperlayer of a selected fluid layer just adjacent top perimeter of the innercontainer, the plunger being in the open position. Subsequent to fluidpositioning, rotation of the external cap can move the plunger to theclosed position. Subsequent to closure, a collection syringe 1110 (seeFIG. 10) or other fluid withdrawal device may be coupled to fluid deviceinterface 144, and the selected fluid may be pushed up by the pistoninto syringe 1110.

Understanding the general function and structure of the plunger assembly131, lid 136, and container-in-container assembly 112, Applicant notesmore specific structure and related function as follows. External cap134 may be seen to contain vents 146 with removable vent caps 148disengaged therefrom. Vents 146 vent pressure differentials from aboveor below the cap, venting responsive to gas pressure differentials aboveand below the cap. The body of cap 134 is seen to have a window 150therethrough. As cap 134 rests on top of fixed lid 136 and is rotatabletherewith, window 150 provides viewing to indicia 164 on the uppersurface of the lid, which indicia indicates with “closed” or “open,” theposition of the plunger (see FIG. 9).

External cover or cap 134 is seen to have a ribbed outer rim 152, whichis easily grasped, and an inner rim 154, which includes depending walls155 defining a bore 154 a. Walls 155 descend downward sufficiently toengage inner lip 161 of lid 136 (see FIG. 5), for example, by resilientwedge elements 155 a on the outer surfaces of walls 155 (see FIG. 5).Thus, external cap 134 is seen to be rotatably “captured” on lid 136with outer rim 152 depending downward over the walls defining the top orupper perimeter 119 of the outer container as best seen in FIG. 8.

With further reference to lid 136 in FIGS. 5 and 7, it may be seen thatinwardly projecting plunger drive bosses 156, typically two opposed onthe inner walls of depending walls 155, are present and are adapted toengage neck 142 of plunger 138 as more further set forth below so as todrive plunger 138 vertically up and down (by virtue of rotation of cap134), without rotating the plunger.

Turning now to lid 136, it is seen to include notched outer rim 160 forsecure engagement with top perimeter 119 and an inner lip 161 forengaging external cap 134 as set forth above. Moreover, inner walls 162of which the inner lip is part thereof, define a bore 162 a adapted toreceive neck 142 therethrough, and neck 142 also is adapted to passthrough bore 154 a of cover 134. Indicia 164 may be found on the topsurface of lid 136. Lid 136 includes anti-rotation tabs 166, which areaffixed to the lower surface of the lid and project both downward fromthe lower surface thereof and inward into bore 162 a in the illustratedembodiment. The anti-rotation tabs are adapted to engage neck 142 ofplunger 138, so as to prevent plunger 138 from rotating responsive torotation of external cap 134 (and thereby for forcing the plunger tomove downward without rotation.)

Turning now to plunger base 140 and as seen in FIGS. 5 and 6, it isintegral with neck 142 and generally cylindrical, having an uppersurface 168 and a lower surface 170. An outer rim 172 may contain agroove 173 for receipt of an elastomeric sealing element 175 (e.g., anO-ring) therein, the base having a diameter such that the outer rim fitssnugly against the inner walls of the outer container 114 as seen, forexample, in FIGS. 7 and 8. The neck and base are integral at neckjoinder walls or area 174, and the upper surface 168 of plunger base 140is seen to have a pair of pockets 176, which are dimensioned and locatedsuch that when the upper surface of the base is flush against the lowersurface of the lid, anti-rotation tabs 166 on the lower surface of thelid fit into pockets 176, allowing a full up or open position of theplunger as best seen in FIG. 8. Pockets 176 may also assist withresisting rotation of plunger 138.

Lower surface 170 of plunger base 140 is seen to contain a circularrecess 192 defining an inner rim 191 with a groove for a sealing element194 (e.g., an O-ring) on the walls of the inner rim, which circularrecess and inner rim 191 is positioned such that in a down, or closed,position as best seen in FIG. 4B, the sealing element located on theinner rim 191, seals against the inner walls of the inner tube justbeneath the open end or open top of the inner tube.

Turning now to the neck 142 of plunger 138 and as best seen in FIGS. 5and 7, it is seen to extend vertically upward from the upper surface ofplunger base 140. Neck 142 includes inner walls 178 defining a bore,which receives fluid device interface 144 fixedly and rigidly therein.Outer walls 180 of neck 142 are seen to include a pair of curved camgrooves or drive tracks 182 a/182 b and a pair of vertical anti-rotationslots 184 a/184 b. Drive tracks 182 a/182 b are configured to eachreceive one boss 156 snugly therein, and anti-rotation slots 184 a/184 b(see FIG. 8) each will accept the inwardly extended portions of theanti-rotation tabs 166 thereinto. Rotation of external cover or cap 134drives the neck and, therefore, the plunger 138 vertically asanti-rotation tabs 166 in the anti-rotation slots 184 a/184 b preventthe plunger from rotating with the cap (and therefore going nowhere inthe vertical dimension). Drive tracks 182 a/182 b being, in part, curvedas they are and the vertical vector of the forces between the bosses andthe drive tracks generating vertical motion, any rotational motion ofthe plunger is prevented by the engagement of the lid 136 withanti-rotation tabs/slots 184 a/184 b. Thus, it is seen how rotation ofthe external cap 134 can move the plunger between an open and closedposition, the open position allowing spillover and the closed positionsealing the inner container. In both positions, and in between, theplunger seals against the inner walls of outer container 114 (see FIGS.4A and 4B). FIG. 9 also illustrates a protruding detent 183 (e.g., aridge) at the upper end of each of drive tracks 182 a/182 b to provide asnap fit for resiliently engaging the boss to help prevent inadvertentrotation of the cap when the plunger is in the closed position. A detentcould also be placed at the bottom of the drive tracks to snap the capinto place when the plunger is in the open position.

Fluid device interface 144 is adapted to receive a syringe on acollection syringe engagement portion 186 thereof. Outer walls 188 offluid device interface 144 are designed to fit snugly and to be glued orotherwise affixed into the bore of neck 142. In certain implementations,fluid channel 189 in the fluid device interface may have a sealing foam190 therein, which sealing foam is responsive to a pressure differentialacross the removed surfaces thereof so as to, in a neutral pressurecondition, prevent fluid from passing therethrough and, in a fluidpressure differential situation, either greater pressure below or abovethe fluid device interface, to allow fluid to flow therethrough. Thestructure and function of fluid-pressure-responsive fluid deviceinterfaces show them to be medical valves in the nature of substitutesfor needle ports, and provide one or two way fluid communication acrossa pressure differential (see website at domain name“halkeyroberts.com”).

Turning to FIGS. 4 and 10, it may be seen that base 122 is configured toseal off annulus 123 and the bottom of inner container 124, while alsoproviding fluid communication from outside the base and into the innercontainer, such that coupling a drive syringe 1112 to base 122 allowsthe user to force a gas or other fluid into the inner container belowpiston 132 and push the piston upward or to withdraw fluid and allowpiston 132 to drop and, therefore, selectively control the position offluids in the inner tube, including separated fluids.

Bottom wall 195 of base 122 fluid sealingly engages the bottom of innercontainer 124. Upstanding wall 196 fits within the annulus 123 and mayhave a top surface 196 a that is tilted toward a rescue vent 198. Rescuevent 198 passes through wall 196 from top through bottom and connects toannulus 123 through a silicon bead or other piercable fluid stop 198 ain the rescue vent. In this manner, rescue vent 198 may be puncturedwith a needle or syringe coming from beneath and up into the annulus soas to withdraw or “rescue” a fluid that was inadvertently spilled overor pushed over the top of the inner tube.

Part of the body of base 122 includes a notch 1100 configured to bereceived in cutouts 117 a and 117 b located at the bottom of the outerand the inner containers. A horizontal channel 1102 through the base 122is adapted to accept fluid device interface 1105 fluidly sealed therein.Threaded portion 1104 of the fluid deivce interface is adapted toreceive syringe 1112 or other fluid containing device (see FIG. 10).

FIG. 10 illustrates a manner in which biological concentration assembly110 may engage a biological fluids transfer syringe 1110 and pistondrive syringe 1112. Biological fluids transfer syringe 1110 has an endfor threaded engagement to the threads of syringe engagement portion 186of fluid device interface 144 for fluid tight coupling therewith.Syringe 1110 may carry an undifferentiated blood or biological fluidspecimen to collection assembly 110, and threaded to the neck of theplunger, this fluid may be transferred into the portion of the innercontainer above the piston. Piston fluid drive syringe 1112 may befilled with a saline solution or other suitable fluid injectable intothe inner container in the space below the piston to advance (drive) thepiston or extract the fluid from the inner container to retract thepiston responsive to movement of the plunger of drive syringe 1112.Either an incompressible fluid (e.g., a liquid) or a compressible fluidsuch as a gas (e.g., air), may be used to advance and/or retract thepiston. Following centrifugation, for example, syringe 1112, withsyringe 1110 secured, can be used to urge piston 132 upward so as todrive a differentiated fluid either into the annulus via spillover(plunger up) or, with a selected fluid adjacent the top of the innercontainer and the plunger in the down or closed position, advancing thepiston upward to drive a selected fluid into syringe 1110.

Although the inventive concepts have been described with reference toexample embodiments, this description is not meant to be construed in alimiting sense. On the contrary, various modifications of the disclosedembodiments will be readily apparent to those skilled in the art uponreference to the description of the invention. Moreover, variousfeatures of each embodiment may be used with the other. For example, theplunger assembly of assembly 10 may be used with assembly 110, and theplunger assembly of assembly 110 may be used with assembly 10. Asanother example, the piston drives are interchangeable. As a furtherexample, a scale similar to the one for assembly 10 may be used withassembly 110. It is therefore contemplated that the appended claims willcover such modifications, alternatives, and equivalents that fall withinthe true spirit and scope of the invention.

The invention claimed is:
 1. A biological fluids concentration assembly,comprising: a tube in tube assembly defining a vertical axis andcomprising a cylindrical outer tube and a cylindrical inner tube, theinner tube having a smaller diameter, with an annulus between the twotubes, both tubes having open tops and bottoms, the open top of theinner tube being located below the open top of the outer tube, and abase engaging the outer tube and the inner tube at the bottom ends and afloor for engaging the open bottom of the inner tube thereof, the basewith a channel for allowing fluid communication between the exterior ofthe tube in tube assembly and the interior of the inner tube; a pistonfor slidably and fluid sealingly engaging the inner walls of the innertube above the base and below the top of the inner tube; a lid forengaging to the open top of the outer tube, the lid having a centralbore and anti-rotation tabs, and a plunger assembly comprising aplunger, a cap with inner rim walls defining a central bore, the innerrim walls having projecting drive bosses, the cap with walls forrotatable engagement with the lid and the plunger, the plunger having abase having an upper and lower surface and a neck, the plunger having afluid channel therethrough, the neck having a track, wherein the trackengages the projecting drive bosses of the cap and wherein theanti-rotation tabs of the lid engage the plunger such that rotation ofthe cap moves the plunger longitudinally without rotating the plunger,the cap moving between an open position wherein the lower surface of thebase is off the open top of the inner tube and a closed position,wherein the lower surface of the base engages the open top of the innertube so as to fluidly seal the open top.
 2. The assembly of claim 1,wherein the assembly base includes an external port, the port engagedwith the channel, the port including walls dimensioned to receive andfluidly couple with a device thereon for injecting and withdrawing adrive fluid into and out of the inner tube below the piston, such thatthe piston moves up and down in the inner tube responsive to suchaction.
 3. The assembly of claim 1, wherein the anti-rotation tabs ofthe lid engage anti-rotation slots of the neck.
 4. The assembly of claim1, wherein the cap includes members for holding the cap to the outertube while allowing the cap to rotate with respect to the tube.
 5. Theassembly of claim 4, wherein the lid includes a perimeter lip on thewalls adjacent the central bore and wherein the cap members for holdingincludes resilient wedge elements for coupling with the perimeter lip ofthe central bore of the lid.
 6. The assembly of claim 1, wherein thebase of the plunger includes perimeter walls for fluid sealinglyengaging the top of the inner tube when the plunger is in the dosedposition.
 7. The assembly of claim 6, wherein the base of the plungeralso includes a perimeter adjacent the inner walls of the outer cylinderto fluid sealing engage the same.
 8. The assembly of claim 1, whereinthe plunger includes a needle free valve engaging the fluid channel suchthat fluid passing through the plunger passes through the needle freevalve.
 9. The assembly of claim 1, wherein the base of the tube-in-tubeassembly includes a rescue vent.
 10. The assembly of claim 1, whereinthe channel of the base of the tube-in-tube assembly includes a needlefree valve.
 11. The assembly of claim 1, wherein the piston has a solidbody with a top surface, a bottom surface, and a perimeter and includesan O-ring adapted to fluidly seal the body of the piston to the innerwalls of the inner tube.
 12. The assembly of claim 1, wherein theannulus is adapted to receive a portion of a biological fluid that mayspill over the top of the inner tube when the piston is moved towardsthe lid.